Multipurpose fixture for abrasive grinding wheels



April 4, 1950 T. H. cHoATE 2,502,705

\ MULTIPURPOSE FIXTURE FOR ABRASIVE GRINDING WHEELS Filed Feb. e, 194s 2 Shee`ts-Sheet l Z6 24 m i Z0 Howl-[Cigogne MSG/m5 April 4, 1950 T. H. cHoATE k2,502,705

' MULTIPURPosE FIXTURE FOR ABRAsIvE GRINDING WHEELS Filed Feb. 6, 1948 2 Sheets-Sheet 2 PILE-:q---y-vk Il Hlm', l

YHQMASHiOATS Patented Apr. 4, 1950 UNITED STATES PATENT OFFICE MULTIPURPOSE FIXTURE FOR ABRASIVE GRINDING WHEELS 1 Claim. 1

'This invention relates to a multi-purpose fixn ture for abrasive grinding Wheels and the primary object of the invention is to provide an attachment used in conjunction with bench grinders to support either a tool or work in cooperative relationship with the abrasive wheel.

In the grinding of valve stem ends the contact face of the abrasive wheel becomes worn and must .be redressed for further use. It is the objective of this invention to provide a xture that first readily supports a valve stem for end grinding but secondly is also adapted to alternatively receive a diamond wheel dresser when redressing of the abrasive wheel face is necessary.

It is also an object of the invention to provide a bench supported quick releasable xture used in conjunction with a bench grinder having an abrasive Wheel which is adapted to support valve stems of different diameters and to securely hold the ends of the valve stems against the face of the abrasive Wheel for grinding.

A still further object of the invention is to adapt the xture to support an abrasive wheel dressing tool and mount that is adjustable therein for accurately redressing the grinding surface of the wheel.

These and other objects of the present invention will appear as the following description thereof proceeds, and in order to more clearly understand the invention, references may be had to the accompanying drawings in which an embodiment of the invention is shown.

In the drawings:

Figure 1 is a perspective view of a bench-type valve grinder illustrating the fixture holding a valve stem in proper position on the grinder for end grinding;

Figure 2 is a vertical transverse sectional view taken substantially upon the plane of the seotion line 2-2 of Figure 1 Figure 3 is a fragmentary View, similar to Figure 2, but showing the holding jaws of the xture in open position;

Figure 4 is a side elevational view of the bench grinder, the fixture and a dressing tool carried therebyrfor dressing the surface of the abrasive wheelof the grinder; and,

Figure 5 is a side elevational View of the dress ing tool and mount in Figure 4.

Referring now more specifically to the accompanying drawings, wherein like numerals desig nate similar parts throughout the various views, I0 designates generally a conventional and vvellknown type of bench grinder, having an abrasive wheel I I carried thereby together with a grinder hood or shield I2 overlying the upper portion of the Wheel and constituting a guard to prevent the injurious emission of abraded articles from contacting the eyes or person of the user. The bench grinder which is of any desired type and preferably includes an electric motor, not shown, for operating the abrasive wheel, is intended to be mounted upon any suitable support such as a bench, and has positioned adjacent thereto the fixture indicated generally at i3 and which constitutes the gist of this invention.

As illustrated in Figures 1-3, this fixture comprises a support, having a pair of parallel vertically extending and abutting standards I4 and I5 respectively, which are preferably rigidly secured together as by rivets It or the like, and which at their lower ends are outwardly anged as at I'I and I8, to constitute a base for mounting the fixture upon the supporting surface of the bench grinder by conventional fasteners.

The inner face of one of the members of the fixture, such as the member I0, is provided adjacent its upper end with a plurality of parallel, transversely extending semi-cylindrical channels I9 and 20 respectively, and preferably below these channels is provided with a suitable bore 2I which screw-threadedly receives the end 22 of a clamping screw 23 having the nger-grip knob or Wheel 24 and a collar 25 thereon.

The other bracket member I5 is shorter than the above mentioned member i4, but has an extension 26 positioned longitudinally thereof and hinged thereto at 21, to thereby provide a movable jaw having channels 2t and 29 complementary to and registering with the above mentioned channels I9 and 20. The upper ends of the fixed and movable jaws are provided with downwardly and inwardly inclined surfaces respectively providing a V-shaped notch when the jaws are closed. Preferably below the channel 29, the movable jaW 2t is provided with a vertically elongated slot 30 which loosely receives the shank 23 of the bolt.

The pairs of registering channels i9 and 28, and 2|] and 20, are of various diameters in order to accommodate various sizes of valve stems, one of which has been indicated at 3| in Figure 1, as secured in the device in operative position with respect to the abrasive wheel.

This valve stem 3! is provided with the customary valve stern and'foot 32 which is adapted to be contacted by the cam of the cam shaft of an internal combustion engine or the like, in order to raise or lift the valve from its seat against the action of its opposing spring. When valves are reconditioned for replacement in their seats, it is frequently found that the foot 32 is not given the desired clearance with the base circle of the operating cam of the valve mechanism, and accordingly, it is necessary to grind the end of the foot 32 until the desired clearance is again provided. In operating this device, the jaw 26 is swung to its open position as shown in Figure 3 by loosening the clamping screw 23, and the valve stem 3| placed in the appropriate valve stem retaining bore in the jaws. The clamp is then tightened and the valve is thus held in proper position against the abrasive wheel Il as the latter is rotated by the grinder ID.

The various sizes of bores in the jaws of the fixture will accommodate dilerent sizes of valve stems rendering the device readily applicable to various types of valves.

Occasionally, it becomes necessary to redress the wear surface of the abrasive wheel il, in order to remove unequally Worn spots therefrom, and provide a true surface for correctly grinding the foot of a Valve stem. For this purpose, the grinder dressing tool indicated in Figures 4 and 5 is provided. 'I'his tool consists of a reduced shank portion 33, which at one end is provided with a. linger-grip knob or wheel 34 for rotating the' shank, and at the other end is provided with a crank arm 35 through which is screw-threadedly adjusted a diamond tool 38 having a knurled or other finger-grip portion 31 at one end and a diamond tool dressing point 38 at the other. The ends of the reduced shank 33 are appropriately spaced to engage the outer surfaces of the xed and movable jaws of the fixture for preventing longitudinal displacement of the diamond tool 36 but to permit rotation of the shank 33 within the appropriate complementary bores of the jaws of the fixture whereby the dressing point 38 may be moved in an accurate path across the abrasive surface of the Wheel Il. As will readily be seen, proper adjustment of the diamond tool may be eected by rotating the same by means of the finger-grip portion 3T, to thus advance or retract the point from the face of the wheel Il.

When employing either the dressing tool or the valve stem grinding features of the invention, it will be seen that the article contacting 4 the face of the abrasive wheel Il will at all times be held at the proper angle with respect thereto, and in a rm and rigid position. Further, the article so contacting the abrasive Wheel may be readily inserted in or removed from the fixture with a minimum of effort.

From the foregoing, the manner of operating and utilizing the device will be readily understood and accordingly, further explanation is believed to be unnecessary. Since numerous changes and modications will readily occur to those skilled in the art after a consideration of the foregoing drawings and specification, it is not desired to limit the invention to the exact construction shown and described, but all suitable modifica tions and equivalents may be resorted to falling Within the scope of the appended claim.

I claim:

A supporting fixture adapted for use in conjunction with an abrasive wheel grinder including a pair of vertically extending abutting standards of unequal length secured together in face to face contact, outwardly iianged feet for said standards to act as a supporting base, an extension pivotally connected with the upper end of the shorter standard adapted to form with the extending portion of the longer standard pivoted and rigid clamping jaws, complementary different sized channels formed on the adjacent faces of said jaws, and a clamping bolt extending through an oversized opening in the extension and threadedly engaged with extending portion of the longer standard.

THOMAS H. CHOATE.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,422,097 Greeniield July l1, 1922 1,912,313 Schwab May 30, 1933 1,951,201 Oakley Mar. 13, 1934 2,248,262 Wilhide July 8, 1941 2,316,591 Johnson Apr. 13, 1943 2,415,575 Brabazon Feb. 11, 1947 2,421,143 Darland et al. May 27, 1947 2,459,910 Alvin Jan. 25, 1949 

